500 plus CID LS engines

[PAUL K]

Any LS fans have experience on the permance of big displacement LS engines?

Pros/Cons?

[Scott65]

No experience, but curious as well. I wonder if the intake tract that is so phenomenal for up to 400", would get small at 500"? I personally know a guy making 620hp @ 402" N/A with cathedral ports( ported). I'd guess that the later square ports would be up to the task at 500". Hope you get some responses with real world experience.

[Gastiresandoil]

Originally Posted by Scott65

No experience, but curious as well. I wonder if the intake tract that is so phenomenal for up to 400", would get small at 500"? I personally know a guy making 620hp @ 402" N/A with cathedral ports( ported). I'd guess that the later square ports would be up to the task at 500". Hope you get some responses with real world experience.

I was at 600 at the tire with a 440 on a N2O tune. The 620 is very possible from a 402 stroker, whether that is motor or rwhp is unclear.

500+ cu is going to be hard. I think the tall deck blocks are in the 480ish range.

[Scott65]

In my example it was flywheel hp. ET/MPH pretty well backs it up, 10.2xx@130. Glass hood, full interior 2000 fbody.

[Scott Roberts]

Zero experience with large ci ls engine..very little with any ls to be honest..lol
Are u looking to build a big inch engine Paul or is ya fishing..
Don't really see a need to go big from what I've seen and experienced with the ls ( limited experience). Got a co worker making 720 (crank hp) on pump gas with 427ci..

[FrankieT/A]

Originally Posted by PAUL K

Any LS fans have experience on the permance of big displacement LS engines?

Pros/Cons?

Hi Paul,
I have been looking into the feasibility of the LSX454 for some time now. Not many people use them but I can't find a reason why. It seems most people use smaller displacement with power adders, mostly turbo. Granted these people are realizing ridiculous HP with turbos on smaller displacement and stock bottom ends.

I'm looking to use large displacement in order to avoid power adders. Info is seems to be limited.

[Scott Roberts]

Originally Posted by FrankieT/A

Hi Paul,
I have been looking into the feasibility of the LSX454 for some time now. Not many people use them but I can't find a reason why. It seems most people use smaller displacement with power adders, mostly turbo. Granted these people are realizing ridiculous HP with turbos on smaller displacement and stock bottom ends.

I'm looking to use large displacement in order to avoid power adders. Info is seems to be limited.

How much power are you after? Just curious..

[FrankieT/A]

Originally Posted by Scott Roberts

How much power are you after? Just curious..

If you're asking me, I'm looking for legit 600 HP with no power adders and not totally strung out.

[Scott Roberts]

Originally Posted by FrankieT/A

If you're asking me, I'm looking for legit 600 HP with no power adders and not totally strung out.

You don't need big ci for that hp level.. I'm sure Paul could chime in here.. he has a lot of experience with the Ls engines and would be a good one to talk with to get you where u want to be..

[FrankieT/A]

Ok I'll bite.

What LS engine is going to give me 600 legit HP with no power adder and not be totally radical? Like a .700 lift cam...

Maybe a 427? At that point for the expense might as well go 454. 427's are not known for their reliability.

[Scott Roberts]

Originally Posted by FrankieT/A

Ok I'll bite.

What LS engine is going to give me 600 legit HP with no power adder and not be totally radical? Like a .700 lift cam...

Maybe a 427? At that point for the expense might as well go 454. 427's are not known for their reliability.

Google is your friend.. my co workers 700+hp pump gas ls is under .700 lift.. are u under the impression higher lift on an engine means lots of maintenance?

[Scott65]

In my example of the 402 @ 620 hp, they don't own a trailer. That car gets driven everywhere. Including back and forth to the track. I think it's in the low to mid .600 lift range.

[Scott Roberts]

Originally Posted by Scott65

In my example of the 402 @ 620 hp, they don't own a trailer. That car gets driven everywhere. Including back and forth to the track. I think it's in the low to mid .600 lift range.

This...that's a fairly mild engine. Ls engines shine on the street.. they do well on the track too but tame 600hp street engines is where they shine

[FrankieT/A]

Originally Posted by Scott Roberts

Google is your friend.. my co workers 700+hp pump gas ls is under .700 lift.. are u under the impression higher lift on an engine means lots of maintenance?

What engine?

[Scott Roberts]

Originally Posted by FrankieT/A

What engine?

416ci... ls3
Not sure of his complete build, but if u want a turn key ls, call texas speed.. 427 with 630+hp for 19.5k...

[PAUL K]

Originally Posted by Scott Roberts

Zero experience with large ci ls engine..very little with any ls to be honest..lol
Are u looking to build a big inch engine Paul or is ya fishing..
Don't really see a need to go big from what I've seen and experienced with the ls ( limited experience). Got a co worker making 720 (crank hp) on pump gas with 427ci..

Just asking in regards to a recent conversation I had with a buddy. He was yapping about how bad azz LS engines are and they will out power bigger Pontiac engines. I was just wondering if any folks had first hand experience with the bigger engines?

Perfer real world information over Google. I've found Google to lead one to believe the Pontiac 557 block with destruct at three hundred horsepower and be safe to a thousand.... Chit there is even info on Google that says Chicago doesn't have a crime problem.

[Scott Roberts]

Originally Posted by PAUL K

Just asking in regards to a recent conversation I had with a buddy. He was yapping about how bad azz LS engines are and they will out power bigger Pontiac engines. I was just wondering if any folks had first hand experience with the bigger engines?

Perfer real world information over Google. I've found Google to lead one to believe the Pontiac 557 block with destruct at three hundred horsepower and be safe to a thousand.... Chit there is even info on Google that says Chicago doesn't have a crime problem.

Lmao... I see what you did there. I'm literally crying..����������.
I bet that guy never pointed to anything over 416ci. Bet he never saw the need too...
I knew u were fishing. Lol
As far as real world, how about 376ci with a blower making 687hp at the wheels and getting 21 mpg on the highway. Pontiac much?
Figured u were fishing. Lol

[PAUL K]

Originally Posted by FrankieT/A

Hi Paul,
I have been looking into the feasibility of the LSX454 for some time now. Not many people use them but I can't find a reason why. It seems most people use smaller displacement with power adders, mostly turbo. Granted these people are realizing ridiculous HP with turbos on smaller displacement and stock bottom ends.

I'm looking to use large displacement in order to avoid power adders. Info is seems to be limited.

Hi Frankie, generally for NA street build displacement is your friend. However at some point, the options that give you displacement starts to take away horsepower itself. Example a 4.5 inch stroke in a factory block Pontiac.
The length of the intake tract will find a sweet spot for CID and RPM range also.

[Scarebird]

625hp, $10,299 for longblock

https://paceperformance.com/i-8396421

525hp, $9,533 straight from the factory with coils, etc.

https://paceperformance.com/i-7739382

Don't need big cubes here. Note the surface of the pistons: lotta Cray time there!

[FrankieT/A]

Originally Posted by Scott Roberts

416ci... ls3
Not sure of his complete build, but if u want a turn key ls, call texas speed.. 427 with 630+hp for 19.5k...

For 13K you buy an 620HP LSX454 long block from GM. Just saying...